The Threat of Further ISIS Terrorism in Europe - Rękawek, Kacper (Polski Instytut Spraw Międzynarodowych, 2016)
ISIS is threatening new terrorist attacks in Europe. These could be carried out by terrorists still on the run and previously involved in the preparation of the last Paris and Brussels attacks. Belgium and France are the most threatened, however, ISIS is also calling on its European followers to stage individual attacks. It mostly counts on the 1,500 or more of its fighters who have returned to Europe from Syria. Any individual actions would not likely match the ferocity of the attacks staged directly by ISIS in Europe between 2015 and 2016; nonetheless, the lone and spontaneous character of such acts could pose a bigger challenge to security services than well-planned attacks